COMPOSITAE COMPOSITE FAMILY 
AMERICAN FEVERFEW 
Parthenium integrifolium L. 
This plant grows in dry open places on prairies and especially 
along prairie borders in wooded regions. It is found from Mary- 
land to Minnesota and south to Georgia and Arkansas, and its 
blooming season is 
May to September. It 
was formerly used in 
medicine and in some 
places is called Wild 
Quinine, as well as 
Prairie Dock and 
Cutting Almond. 
It is perennial by 
tuberous under- 
ground stems. The 
flowering stem is 1-4 
feet high, rather stout 
and covered with fine 
hairs near the branch- 
ing top but usually 
smooth below. The 
leaves are ovate or 
ovate-oblong, acute 
Or acuminate at the 
apex, round-toothed, 
rough on both sides 
and firm; the lower are 
petioled and often 1 
foot long and 5 inches wide, whereas the upper are much smaller, 
sessile and partly clasping. 
The heads are numerous in a dense flat-topped inflorescence. 
The involucre is hemispherical and its firm bracts are arranged 
in 2 series, the outer oblong and very hairy, and the inner broader 
and nearly smooth. The receptacle is cone shaped and covered 
with very thin chaff. Very short white corollas characterize the 
5 ray flowers, which are pistillate and fertile. The disk flowers 
are staminate with imperfect pistils. The akenes are slightly 
flattened, margined and crowned by the persistent rays. 
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